abstract:The paternal age effect can refer to the statistical relationships of: (1) a man's age to sperm and semen abnormalities; (2) a man's age to his fertility; (3) a man's age to adverse pregnancy outcomes in his female partner (including miscarriage and fetal death); (4) a father's age at the birth of his offspring on the probability of an adverse birth outcome (such as low birthweight); or (5) a father's age at the birth of his offspring on the probability that the offspring will have a health-related condition (e.g.